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Urban Prairie Dog Population Management Using Non-Lethal Reproductive Control
Dan Salkeld, Jackson Runte, Douglas Eckery, Gary Witmer, Aaron ShielsColorado State University & National Wildlife Research Center, USDA-APHIS
Photo: Rose Lombardo
Black-tailed prairie dogs (Cynomys ludovicianus)
• One of five species of prairie dogs in North America
• Great Plains habitat
• Keystone species
Photo: M. Lockhart
Burrowing owls
Conservation status: Threatened
“Management efforts directed
toward retention of active prairie
dog towns and cropped vegetation
(
Prairie dog density higher in urban colonies (compared to more natural, unrestricted populations).
Current Solutions
Lethal Control
• Poisoning
• Fumigation
• Raptor perches
Non-lethal Control
• Relocation
• Barriers
Can we use an immunocontraceptive?
GonaCon – a gonadotropin releasing hormone (GnRH) immunocontraceptivevaccine
Injection of GnRH hooked with a foreign protein
Causes the bodies immune system to bind to GnRH and stop production of sex hormones (estrogen, progesterone, testosterone)
Successfully tested on: white tailed deer, California ground squirrels, Norway rats, cats, dogs, swine, horse, and elk
Administration of GonaCon
Individuals captured, Fall 2018
0.4 mL of GonaCon, or sham (saline) injected into upper thigh of adult females
PIT tags for individual recognition
Matched pairs: Gonacon vs sham vaccine (exp. control)
Gonacon: 25Exp. control: 6
Gonacon: 13Exp. control: 14 6
Gonacon: 27Exp. control: 23 6
FORT COLLINS DENVER
Visual count ratiosField scans of juveniles:adults in May/June 2019(corrected by observations of randomly placed colored mason jars)
0
0.5
1
1.5
2
2.5
3
3.5
Hogbacks SoFoCo Bluff Lake
Ratios of juvenile:adult abundance
Gonacon
Exp. Control
Lower abundance of juveniles in Gonacon sites
Visual count ratiosField scans of juveniles
0
0.5
1
1.5
2
2.5
3
3.5
Hogbacks SoFoCo Bluff Lake
Ratios of juvenile:adult abundance
Gonacon
Exp. Control
Sham (Exp. Control) GonaCon
F = 37.95P < 0.0001
Recapture dataCaptures of juveniles
Lower abundance of juveniles in Gonacon sites
0
1
2
3
4
5
6
7
8
9
Hogbacks SoFoCo Bluff Lake
Number of juveniles captured
Caveats
Field-work finished on Friday!
Statistical analyses (population estimates etc.) begin in earnest…
Blood analyses
Potential as management tool? Models (Yoder et al. 2008) suggest approx. 33% annual contraception could work; or 86% every three years…
In combination with culling?
Discrete, urban prairie dog colonies more likely to realistically managed
EPA product registration
Acknowledgements:Funding from:
Brilliant field-assistance:
Jessie Earhart, Jesika Feldman, Kayla Kolber, Gabby Smuts, Linnea Salkeld, Freya Salkeld, Danika Spock, Ben Thomas, Carly Manthei
Permissions from:
Bluff Lake Nature Center
Fort Collins Natural Areas
EPA & Colorado Parks & Wildlife